(19)
(11) EP 1 355 312 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
28.03.2007 Bulletin 2007/13

(43) Date of publication A2:
22.10.2003 Bulletin 2003/43

(21) Application number: 03250681.8

(22) Date of filing: 03.02.2003
(51) International Patent Classification (IPC): 
G11B 21/10(2006.01)
 G11B 5/596(2006.01)
(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PT SE SI SK TR
Designated Extension States:
AL LT LV MK RO

(30) Priority: 18.04.2002 JP 2002116600

(71) Applicant: FUJITSU LIMITED
Kawasaki-shi, Kanagawa 211-8588 (JP)

(72) Inventors:
  • Ashikaga, Hiroshi, c/o Fujitsu Limited
    Kawasaki-shi, Kanagawa 211-8588 (JP)
  • Suzuki, Nobuyuki, c/o Fujitsu Limited
    Kawasaki-shi, Kanagawa 211-8588 (JP)

(74) Representative: Fenlon, Christine Lesley et al
Haseltine Lake & Co., Imperial House, 15-19 Kingsway
London WC2B 6UD
London WC2B 6UD (GB)

   


(54) Disk device and disk medium


(57) A disk device and a disk medium in which a plurality of servo cylinders (20) on the surface of at least one disk (10) are divided into several areas (P0,P1) and a different servo signal frequency (FS0, FS1) is set and recorded for each of the areas (P0,P1). The servo cylinders (20) are divided into predetermined areas (P0,P1) and a different servo signal frequency (FS0,FS1) for each of the areas (P0,P1) is set so that the recording density of the servo signals recorded in the disk (10) can be set so as to allow the servo signal demodulation characteristic to be included in a relatively superior range. In such a disk device, the boundary between the area (P0) of a first servo signal frequency (FS0) and the area (P1) of a second servo signal frequency (FS1) adjoining the first servo signal frequency area (P0) is preferably formed with an area in which a servo signal pattern written with the first servo signal frequency (FS0) and a servo signal pattern written with the second servo signal frequency (FS1) are arranged on the same servo cylinders (20).







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